meson: Add '@EXTRA_ARGS@' to generate_test_runner arguments

Extended the argument list in meson generator for the test
runner strict by adding '@EXTRA_ARGS@'. This change enables the test
runner script to accept additional configuration parameters alongside
'@input@' and '@output@', increasing its flexibility.

Author: Dominik Loidolt

meson.build

@@ -76,5 +76,5 @@ endif
 gen_test_runner = generator(
   find_program('auto/generate_test_runner.rb'),
   output: '@BASENAME@_Runner.c',
-  arguments: ['@INPUT@', '@OUTPUT@']
+  arguments: ['@EXTRA_ARGS@', '@INPUT@', '@OUTPUT@']
 )